<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>Title</title>
    <script src="observer.js"></script>
</head>
<body>
<script>
    // var obj = {
    //
    // };
    // obj.log = console.log;
    // obj.log.call(console,this);
</script>
</body>
</html>